Zinc furnace



July 18,. 1933.

E. H. BUNCE ET AL A I1,918,245

ZINC FURNACE Filed May 29, 195o 2 Sheets-Sheetv 1 July 18, 1933. E. H. BUNcE Er AL ZINC FURNACE 2 Sheets-Sheet 2 Filed May 29, 1930 ATTORN EY retener my ia, 193e L E. BUNCE AND PHILIP H. GINDER, 0F .a f

EEN, PENEYLW TD THE NEW JERSEY Zm WANT, @F YUBK, N. Y., A! WOMTIION Oli NEW JERSEY ZIN WRNA Application Med Hay tt,

rlhis invention relates to zinc furnaces and has for its object the provision of certain improvennnits` in retorts for smelting ainciterous materials, and in particular for the dis tillation of Zinciferous materials.

The invention is especially applicable in the construction of vertical built-up zinc re" torts of the type described in ll. S. Patent,- No. 1,680,726, August 1l, 1928, to Breyer and- Bunce, though not limited thereto. I'llhat patent describes a vertical retort structure built up oit temperature resistant briclrl cemented together with plain butt joints. Illie a or the present invention is to render auch a atrncf-A ture more resistant to the inevitable temperature changes and resulting expansion and contraction that are incident to its use. The expansion and contraction 'produced by temperature changes result in stresses and strains which tend in the long run to crack the masonry et such a retort and thus shorten its lite. According to the present invention, the stresses and strains produced by expansion and contraction are lessened and localized by iitting the Walls of the retorts together with vertical slip joints more particularly de- "scribed hereinafterz rlhese slip 'joints are so constructed that each wall of the retort has room to expand and contract both horizontally and vertically without transmission oit the movement tothe adjoining Walls with consequent production oi stresses and strains. ln other Words, the destructive interplanar stresses which would otherwise occur at the `corners of retorts of rectangular cross-section are avoided by the walls being permitted to move in their own planes. p

Slip joints, according to the invention, are constructed as`follows: A slot isl toed in one Wall into which another wall ts. At the pointjrwhere the entering VWall ts into the slot,;the edges ofthe slot approach it'closely enough to form an adequately tight jointr However, the slot ist so constructed that the wall entering it is notr in close contact with the entire inner surface of the slot. The slot is also deep enough to permit free expansion of the entering wall in a horizontal direction. Such a slot thus forms a structure resemblingy a stuffing box or gland. The stuing-lbox or verulent refractory material which will not sinter or frit and so cause the Walls to become rigidly cemented together. Suitable mate,- rlals orthis purpose are powdered silicon carbide, graphite, granular alumina and the like. iatures of naked aphite and powdered graphite orof si icon carbide and graphite are also suitable. Such a lling material has been used in vertical zinc retorts constructed in accordance with the invention tor nine months Without sintering or tritting.

While the use ot such a pulverulentl sealing material in the stug-box slip j oint of. the invention is dat present our preferred practice, it is to-be understood that its use is by no means essential. 'lhe stug-box can be left empty sin/cle when such a vertical retort is operated the zinc'vapor that seeps into the slip joint soon becomes oxidized to zinc oxide by 'Contact either with the air or with oxidizing gases in the combustion chamber surrounding the retort or adjacent to it. This,-

zinc oxide'together with small amounts of plastic glaze and slag that form on the surlace of refractory materials Whenheated to the temperature at which a zinc smelting retort is operated, and when in contact with a zinc retort charge, forms a suitable seal.

Such a slip joint will, shortly alter the retort has been put in operation, support, an internal pressure et somewhat more than 1/2 inch of Water without permitting any substantial l leakage of zinc vapor.` This degree off zinc vapor tightness is adequate for ordlnary practice since vertical zinc retorts are commonly operated at an internal pressure of 0.3 inches of water. v p

Y ln case the joints are filled With the pulverulent material described above, their edges are luted slightly with clay as the pulverulent material is put in so that it will not run out of the joint. Care is taken not to apply enough clay luting to bind theatvvo Walls rigidly together.

aThe invention will be better understood reference to the accompanying drawings 1n which v Fig. lis a cross-section of a rectangular vertical zinc retort with four stuing-box slip joints constructed in accordance with the invention;

Fig. 2 is a perspective View of the top of the retort;

Figs. 3, 4, 5 and 6 are cross-sections o rectangular retorts embodying various modications of the stulling-box slip joint of the invention.

In the drawings, numeral 40 indicates the end walls of the vertical retorts (which may or may vnot be at the same time the end walls of the combustion chambers for heating the retorts), and numeral 41 indicates the side walls of the retort. The side walls are shown as built of vmasonry but they may likewise consist of plates of refractory metal. The side walls 41 fit into slots 42 located in the end walls. The slots 42 are only slightly widerthan the thickness of the side wall at thepoint where the side wall enters the slot; but the slot is widened a short distance beyond the point of entry of the side wall to form two open spaces 43 and 44. As will be seen by the drawings the slot is likewise so deep that there is substantial clearance between the end of the side wall and the bottom Y of the slot, so that an open space is left as shown at 49. These open spaces, in particular at 43 and 44, are shown as filled with pulverulent sealing material I(for example one of the hereinbefore described mixtures of silicon carbide and graphite). However, these spaces may, in certain circumstances, be left empty; in whichcase the zinc oxide formed by theoxidation of the zinc vapor seeping through and the"s1ag formed on the retort walls will automatically form an efficient sealing material soon after the retort has begun to operate.- I

It will be understood that the particular arrangement of brickwork shown in the drawings is merely illustrative, and that the slip joints of the invention can be constructed by -other methods of brick-work construction, as will be evident t0 those skilled in the art.

Figure 3 shows a cross section of a vertical zinc retort in which the slip joints are provided with only one open space 44 to serve as a container for the pulverulent sealing ma.- terial, instead of two open spaces. It will of course be understoodthat an open space 49 must be left betweenthe end of the side wall 41 and the bottom of the slot 42 as in the construction shown in Figures 1 and 2.

Figure 4 shows two retorts set end to end with a partition wall 45 containing slots 46, similar to the-slots in the end wall 40, for receiving the side walls 41. In the'case of these slots 46 no open spaces are provided except the wide open space between the end of the side wall and the bottom of the slot. Two dierent forms of constructing the slots are shown at the right and left of the parti-4 tion wall, respectively. U

Figure 5 shows a form of construction 1n which the side walls of the retort are built in two or more. sections separated yby columns 47 containing slip joints 46 similar to those shown in Figure 4.

Figure 6 shows a form of retort in which the side walls are divided into two sections fitted together by a slip joint 46, the slip joint being formed by a slot in the widened end 48 of one wall into which the narrowed end of the other side wall fits. The purpose of reducingl the thickness of the side wall where it enters the slot is to reduce the overall "thickness of the slip joint.

It will be understood that the particular forms of construction shown are given merely for the sake of example. The invention is based on the surprising fact that zinc retorts can be constructed so as to be Zinc vapor tight by joining the walls together with slip joints so construct-cd that only part of the two adjoiningr walls are in contact at the joint, open spaces being left in the joint so that ample room is left for expansion, contraction and slip ofthe walls. Such construction increases theV durability of the vertical zinc retorts since the tendency of the retortsy to crack on account of the stresses and strains set up by the differential expansion and contraction of the walls is minimized.

We claim:

1. A chamber for producing zinc vapor comprising a plurality of walls of' temperature-resistant material so connected one to the other that each wall may independently .expand or contract, one wall of each adjacent vpair of walls being provided with a stuing box into which the other wall fits to form a suiliciently tight joint to prevent the escape of zinc vapor from the'chamber.

2. A zinc reduction chamber comprising a plurality of walls of temperature-resistant material so connected one to the other that each wall may independently expand or contract. one wall of each adjacent pair of walls being provided with a recessed channel into which the .end of the other wall ts to form a su'icientlytight'joint to prevent the escape of zinc vapor from the chamber.

3. A chamber for producing zinc` vapor comprising a plurality of walls of tempera.-

v{ture-resistant material so connected one to the other that each wall may independently expand or contract, one wall of each adjacent pairof walls being provided with a stufling box into which the other wall fits to form a sufliciently tight joint to prevent -the escape of metal zinc from the chamber, the free space between the Walls in the stuffing box being filled with heat-resistant material adapted to provide a vapor-tight joint.

4. A zinc reduction chamber comprising a plurality of walls of temperature-resistant material so connected one to the other that each wall may independently expand or contract, one wall of each adjacent pair of walls being provided with a recessed channel into which the end of the other wall lits to form a sufliciently tight joint to prevent the escape of zinc vapor from the chamber, the freespace l between the walls within said channel being filled with heat-resistant material adapted to provide a zinc vapor-tight joint.

5. A chamber for producing zinc vapor comprising a plurality of `walls of temperature-resistant material so connected one to the other that eachwall may independently expand or contract, one wall of each adjacent pair of walls being provided with a stufling box into which the other wall fits to form at one place a snug joint and at another'place a free space between the walls, the free space between the `walls in the stufiing box being iilled with pulverulent material adapted to retain zinc vapor under normal operating conditions.

6. A zinc reduction chamber comprising a plurality of walls of temperature-resistant material so lconnected one to the other that each wall may independently expand or contract, one wall of each adjacent pair of walls being provided with a recessed channel into which the end of the other wall fits to form at one place a snug joint and at another place a free space between the walls, the free space between the walls in the channel being filled .with pulver'ulent material adapted to retain Zinc vapor at the normal pressure of zinc distillation within the chamber.

. 7 A vertical zinc retort of polygonal crosssection the walls of which fit together in substantially vertical joints provided with a seal .of pulverulent material adequate to retain zinc vapor at the normal pressure of zlnc distillation.

8. A vertical zinc retort of polygonal crosssection comprising walls having oints therebetween in which the points of contact of adjoining walls enclose open spaces in the joints between the walls.

9. A vertical zinc retort of polygonal crosssection comprising walls having joints therebetween in which the points of contact ofadjoining walls enclose open spaces in the jolnts between the walls, said open spaces being filled with heat-resistant material adapted to provide a zinc vapor-tight joint.

10. A vertical zinc retort of polygonal cross-section comprising walls having joints therebetween in which the points of contact of adjoining walls enclose open spaces in the joints between the walls, said open spaces being filled with a sealing material containing atleast one of the following: silicon carbide and graphite.

11. A chamber for producmg zinc vapor comprising a plurality of walls of temperature-resistant material so connected one to the other that each wall may independently expand or contract, the points of contact of adjoining walls enclosingopen spaces in the joints between the walls.

12. A chamber for producing zinc vapor comprising a plurality of walls of tempera ture-resistant material so connected one t0 the other that each wall may independently expand or contract, the points of contact of adjoining walls enclosing open spaces in the joints between the walls, said open spaces being filled with heat-resistant material adapt ed to provide a zinc vapor-tight joint.

13. A vertical zinc retort of quadrangular cross section having two refractory end walls and at least one metal side wall, the I netal side wall fitting into stuffing box slip jolnts in the end walls in such a way'that the joints are substantially impermeable to z1nc vapor at normal distillation pressures.

14. In a vertically disposed zinc reduction retort, the combination comprising a plurality of walls each of which is built up of a multiplicity of temperature resistant brick, said walls beingso connected one to the other that each wall may independently expand and contract, one wall of each adjacent pair of walls being provided with a vertically recessed channel into which awertical end of the other wall fits.

15. vertically disposed reduction retort according to the the retort is divided into a plurality of chambers separated by a dividing wall, said divid- 111g wall connecting with opposite walls of the retort by means of a slip joint that is substantially zinc-vapor-tight.

1t. In a zincreduction retort, the combinatlon comprising a vertical retort defined by a plurality of vertical walls, said vertical walls fitting together in vertical slipjoints formed by vertical channels into which adjacent walls fit snugly and which are substantially zinc-vapor tight under normaloperating conditions.

17. Inf a zinc reduction retort provided Wlth a plurality' of walls, the combination comprising a slip-Joint for joining the walls of the retort, said slip-joint being provided preceding claim, in Iwhich with a sealing material consisting at least in comprising a slip-joint for joining the'walls i of the retort,^said slip-jointbeing provided with 'a sealing material consisting at least in part of silicon carbide.

' EARL H. BUNCE.

PHILIP M. GINDER. 

